Moore's Law is probably still going for a bit, with current technology should go until 2024 - 2026. I think Nvidia claimed it's dead, and Intel claimed it was not dead shortly afterward. Depends on the exact definition.

Doesn't really matter though, I find it hard to believe these companies will just pack it in, and give up. They'll figure something else out, they've had decades of research go into it.

While it's also not the be all end all of anything either, it's just an easy to digest concept of exponential growth in tech; don't rule out AI from assisting in figuring out new architecture.

On the GPU side I think we mayyybe will get one more doubling of performance within the next few years. But yeah after that improvement will likely start slowing as it seems like Nvidia has already pulled out all the stops with the 4000 series. (Power consumption and card size are reaching insane levels).